Christianity emerged from Judaism. This article inquires how dialogue was conducted with the Jewish confession that the Lord is One. According to this article this did take place frequently, as is evident in the use of the Shema in many New Testament passages (e.g., Romans 3:27-31), and it was also a flashpoint of debate between the church and the synagogue in the first century. It actually became an impetus of early Christian theological development and in particular in confessing the identity of Jesus Christ.